The present invention relates generally to a stabilizer bar for a vehicle suspension system having a direct connect insert which expands as a linkage bolt is torqued within the insert, anchoring the insert within the stabilizer bar and attaching the stabilizer bar to the linkage bolt.
Vehicles are commonly equipped with suspension systems for absorbing road shock and other vibrations, while providing for a smooth and comfortable ride. A stabilizer bar is often used to increase roll rigidity and to improve the steering stability of the vehicle. The stabilizer bar is installed across the frame of the vehicle to control sway when the vehicle turns.
Various types of connections have been utilized to connect a stabilizer bar to a vehicle. In a first type of connection, ends of the stabilizer bar are heat formed, welded, or crimped to an attaching linkage. Another type of connection utilizes a rubber bushing which is attached around the exterior surface of the end of the stabilizer bar. This type of connection pinches into the rubber bushing. In a third type connection, a threaded linkage bolt is inserted into the end of the stabilizer bar and torqued, threading the linkage bolt directly into the interior surface of the stabilizer bar.
Each of the abovementioned methods of attachment have drawbacks. If the ends of the stabilizer bar are formed, welded, or crimped to the attaching linkage, additional detail to the ends of the bar is required, resulting in extra time and expense. The captured rubber bushing is not an acceptable attachment for many applications.
It is also disadvantageous to thread the linkage bolt directly into the interior of the stabilizer bar. This threading operation requires that the stabilizer bar be of a specific inner diameter such that the linkage bolt contacts and threads into the interior surface of the stabilizer bar. Therefore, either the thread size of the linkage bolt or the inner diameter of the stabilizer bar must be altered for a proper fit.
The stabilizer bar must consist of a material of a certain hardness in order to permit threading. If the stabilizer bar is too hard, the linkage bolt will be unable to thread into the interior surface, creating a weak fit. The hardness of the stabilizer bar is increased by heat treatment. Small stabilizer bars have a low stress design and do not require heat treatment. However, if a larger stabilizer bar is needed, heat treatment is required. Thus, with the prior art threading specific attention must be given to the heating process to insure that the ends of the stabilizer bar are not heated and therefore hardened.
Hence, there is a need in the art for a stabilizer bar connection method which does not require complex machining operations.
An inventive embodiment includes a stabilizer bar with a direct connect insert installed into the end of a stabilizer bar to receive a threaded linkage bolt which connects the stabilizer bar to the vehicle. As the linking bolt is torqued, the threads of the linkage bolt penetrate the insert, causing it to expand outwardly towards the interior surface of the stabilizer bar, creating an interference fit.
In a first embodiment, the insert is placed into the end of a stabilizer bar. The insert is comprised of a generally cylindrical shaped body portion having a slightly smaller diameter than the inner diameter of the stabilizer bar. An annular cap has a diameter larger than the inner diameter of the stabilizer bar and abuts the end of the stabilizer bar. A uniform aperture of sufficient diameter to receive a linkage bolt extends through the body portion and the cap of the insert. As a linkage bolt is torqued inside the aperture of the insert, the insert expands outwardly towards the interior surface of the stabilizer bar. This anchors the insert within the stabilizer bar and secures the end of the stabilizer bar to the linkage bolt.
In another embodiment, the insert is placed into the end of a stabilizer bar which tapers at its end, creating a shallow extrusion. This extrusion creates a shoulder that allows for improved anchoring of the expanding insert within the stabilizer bar as the locking bolt is torqued, increasing the locking ability of the insert within the stabilizer bar.
Accordingly, the present invention provides a stabilizer bar direct connect insert composed of an expansive material which is added to the end of a stabilizer bar in order to attach the stabilizer bar to a threaded linkage bolt.
These and other features of the present invention will be best understood from the following specification and drawings.